DE 10 2011 056 790 A1 describes a parabola trough collector. Solar radiation is collected with such a collector and reflected towards an absorber pipe. A heat carrier medium circulates in the absorber pipe. The parabola troughs are provided with a carrier structure carrying mirror elements which are moved according to the solar movement. The parabola troughs are held on pylons. One of the respective pylons is provided with a belt drive thereby forming a driving pylon engaging at an end of the parabola trough. For maintaining the parabolic cross section over the entire length the reflector is pre-formed in such a way that the parabola is formed only after the impact of the twisting.
Known parabola trough collectors are relatively large. They require many efforts for installation. Furthermore, it is difficult to maintain a precise shape over the entire length of the parabola trough.
The working life time of known solar collectors is essentially determined by the environmental conditions which the collectors are exposed to. Overheating will excessively strain the components. Strong winds cause forces and vibrations which may damage mechanical components with the course of the time. Condensation of water vapor at the reflector or its cover will cause absorption or reflection of solar radiation and thereby reduce the usable energy.
US 2009/0314283 A1 discloses solar collectors where light is focused on a pipe by means of elongated mirrors. Furthermore, engines are provided to move the assembly after the solar position. The document discloses the movement of the assembly according to the position of the sun. Measures to protect the assembly from environmental impact are limited to a transparent cover and sealings in connections.
WO 2010/142666 A2 discloses solar collectors where light is focused on a pipe by means of reflectors. The pipe is held in holders which are arranged in periodic distances along the reflector. Furthermore, a movement is disclosed in accordance with the solar position.
WO 2013/028522 A3 discloses solar collectors where light is focused on a pipe with reflectors. The reflector sits in a frame which is rotatably mounted on pylons. An engine causes a movement. The pipe is fixed to the frame with fixings. The frame is rotated by means of the engine. Furthermore, sensors are disclosed for controlling the movement in addition to or instead of a stored algorithm.
WO 2012/128877 A2 discloses a large, open solar collector assembly arranged in a glass house. The reflectors as well as the pipes are suspended from a structure which is formed by the roof of the glass house or the like. A rotating connection is used for this purpose. The weight is held by the roof. The reflectors have several portions and are mounted at the point of use. For this purpose fixing elements and adjustable cables are provided. The positions of the reflectors suspended at cables can be adjusted by pulling the cables by means of a pulley.
WO 2011/141737 A2 describes a reflector assembly with an actuator. The reflector rotates about a focal axis with the pipe. The reflection assembly is rotatably held by a fixed frame through a bearing and the pipe is guided through a pin ring and a worm gear without having any contact thereto. It is a disadvantage of the assembly that the pipe must be opened at least once to insert the pin ring and the worm gear. An installation and pre-adjustment as a whole is not possible with this assembly.
WO 2007/146183 A2 discloses a closed reflector assembly where the reflector is arranged inside a housing with a track-shaped housing bottom. Supports are mounted at the track holding the pipe. The sun is tracked by the assembly with a belt at the track. The force is transmitted on the track or rotatably born end faces of the reflector assembly. In the same way WO 2009/146215 A2 and WO 2012/025849 A2 disclose assemblies where the sun is tracked by a reflector with a belt.